Intubation is a procedure used to secure an airway for patients who are not breathing adequately on their own. The most common route used in performing an intubation procedure is the orotracheal route in which an endotracheal tube (“ETT”) is passed through the mouth and into the trachea in order to facilitate ventilation to the lungs and/or maintain an open airway to administer drugs.
Intubation is commonly performed by direct visualization, which requires the physician or operator to confirm the tube placement by visually verifying that the tip of the tube has passed through the glottis into the trachea. Further, many physicians use laryngoscopes (e.g., conventional, fiber optic, or video) to move the patient's tongue and epiglottis out of the way to provide a better view of the glottis. In the most basic sense, a laryngoscope is a flashlight, and thus, it only aids the physician visually.
While an intubation procedure is routine in an anesthesia setting, the procedure can present difficulties (e.g., in emergency situations where a less experienced individual is performing the procedure). Inserting the endotracheal tube in the esophagus rather than the trachea is the most common error of the intubation procedure due to the relative locations of the trachea and esophagus. In particular, the pathway to the trachea starts in the oral cavity. The back of the oral cavity is called the pharynx, which is considered the start of the throat, and the openings to the trachea and the esophagus are located at the base of the pharynx. The trachea is anterior to the esophagus. In order to properly place the tube in the trachea, physicians must angle the tube upward (i.e. toward the anterior side of the patient's body) while intubating a patient. If the physician cannot clearly see the vocal cords, which are located at the entrance to the trachea, then it is likely for the tube to end up in the esophagus because it presents an easier route for the tube to travel from the pharynx. Complications arising from a tracheal intubation procedure are most common in infants, children, and adult women (due to the relative small larynx and trachea). Additionally, patients who have a difficult airway, congenital/chronic diseases, and/or are obese are more prone to improper placement of the endotracheal tube.